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hey guys just stripped my forged 30det to inspect before it goes in, i just ordered arp head studs and was wondering what a good head gasket would be?? i found a 1.1mm cosworth one pretty cheap, would this work or should i use a genuine 30 or 26 one??

it also has an N1 oil pump in it with 2mm middle restrictor, 1.8mm rear and the vct feed is 1.65mm, would i need smaller?? it has an external head drain fitted aswell, cheers guys

In the RB30 DOHC guide is says if you have an rb25 head to use two 1mm restrictors and if you are using an rb26 head you use 1x 1.5 mm restrictor, i think i read sydney kidd wrote somewhere that you can just block off one but dont quote me on that.
Anyone know where you can get the restrictors from?

  • 2 weeks later...

You don't have a 'head drain', you have a crankcase ventilation pipe. Restricting oil to the top end of a hydraulic head is a fairly silly thing to do. If you have converted to solid lifters or have the Neo 25 head, then this is not so much a problem. They need the quantity of oil in the head for a reason and this was designed into them because smart people know what they are doing. The absolute best thing you can do to stop oil from venting into catch cans is to have adequate ventilation from the crankcase (block) and adequate baffling in the cam covers. I would suggest an RB26 cam cover changeover and fit the Mines or Hi-Octane baffle kit. This kit, along with your ventilation pipe is all you need.

If you must bang restrictors into your block, just use the Tomei ones. They bring the size from 2mm down to 1.5 which is a substantial decrease in oil quantity.

You don't have a 'head drain', you have a crankcase ventilation pipe. Restricting oil to the top end of a hydraulic head is a fairly silly thing to do. If you have converted to solid lifters or have the Neo 25 head, then this is not so much a problem. They need the quantity of oil in the head for a reason and this was designed into them because smart people know what they are doing. The absolute best thing you can do to stop oil from venting into catch cans is to have adequate ventilation from the crankcase (block) and adequate baffling in the cam covers. I would suggest an RB26 cam cover changeover and fit the Mines or Hi-Octane baffle kit. This kit, along with your ventilation pipe is all you need.

If you must bang restrictors into your block, just use the Tomei ones. They bring the size from 2mm down to 1.5 which is a substantial decrease in oil quantity.

im only worried about the oil control because it has an n1 pump which increases presure and flow, even with the restrictors it will have plenty of oil to the lifters i just dont want it pumping it all into the head at sustained high revs, plus this is all precaution i havent ran this setup yet hence why i wanna get it right the first time!! at this stage im more worried about what head gasket to use

I don't have any experience of the Cosworth head gasket but I don't think its critical so long as both surfaces are flat. I am using a Tomei 1.5 gasket.I don't like those "head drain" fittings - I have two breathers on the sump. Read the last few pages of this:<br />http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/?hl=sk%20oil%20control<br /><br />I have an N1 pump in my RB30/25 and use 2 x 1.0mm restrictors (you can buy them from me).

I don't have any experience of the Cosworth head gasket but I don't think its critical so long as both surfaces are flat. I am using a Tomei 1.5 gasket.I don't like those "head drain" fittings - I have two breathers on the sump. Read the last few pages of this:<br />http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/?hl=sk%20oil%20control<br /><br />I have an N1 pump in my RB30/25 and use 2 x 1.0mm restrictors (you can buy them from me).

I don't have any experience of the Cosworth head gasket but I don't think its critical so long as both surfaces are flat. I am using a Tomei 1.5 gasket.I don't like those "head drain" fittings - I have two breathers on the sump. Read the last few pages of this:<br />http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/?hl=sk%20oil%20control<br /><br />I have an N1 pump in my RB30/25 and use 2 x 1.0mm restrictors (you can buy them from me).

well the cosworth seems similar spec to the tomei, still multi layer and cheaper, the only reason i was looking at it cuz its about the thinest i can find which is what im after cuz my forgies are at 8.1 so i wouldnt mind squeezing just a touch more, plus the heads gunna get a skim and its on e85 so the comp will work, i hear lots of ppl saying there not fans of the head drains why is that?? how do i go about purchasing two 1mm restrictors off ya mate??

  • 1 month later...

im guessing the drains as people call them, aren't liked when people don't do them properly...

or have no idea what they are for..they are not to drain oil back...

its -16 in size(not -10 or some f**king shit) with one or 2 of them from rocker cover to sump done properly...

one usually does the trick

cheers

darren

Edited by jet_r31

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